If you believe what you see in the movies, she's white, likes boys, looks way older than she is, doesn't have any career ambitions, and spends more time on housework than homework.

That's the gist of a new report from the the Media Diversity & Social Change Initiative at USC's Annenberg School for Communication and Journalism, which analyzed depictions of girls between age 6 and 20 across the top 900 movies of the last decade, and took an especially close look at the top 200 films from 2015 and 2016.

In most movies, the report found that portrayals of girls fall prey to some of the most insidious gender stereotypes our culture has. You're more likely to see a girl in a movie doing chores or taking care of her siblings than you are to see her studying—and when she is studying, it's usually "girly" stuff, not STEM subjects. Only around 7 percent of young girls in movies ever talk about their career ambitions.

Girls are also four times as likely as their male costars to be pictured in revealing clothing and twice as likely to be shown partially naked. More than half of female teens were actually played by adult actors, so when girls compare themselves to the actor onscreen, they're lining themselves up next to an adult who is more physically and emotionally developed than they are.

And even though there have been some breakthroughs for representation onscreen recently—Wonder Woman, anyone?—that hasn't extended to portrayals of teens and girls. Out of the top 100 movies of 2016, only eight featured girls in leading roles—which is hardly better than the seven girls who starred in films in 2015 or the 6 girls who starred in films way back in 2007. And across all three of those years, only two leading characters were young girls of color. Girls with disabilities and the LGBTQ youth were hardly represented in film at all.

That's despite the film industry's recent revelation that—shocker!—diverse casts actually help movies succeed. (Think: Hidden Figures and the aforementioned Wonder Woman.) But most of the films that we celebrate for their diversity are about women, not girls. That's still great, of course, but this report shows that all the progress that's been made toward better representation in film hasn't extended to the way young people are portrayed. (The report didn't cover television, where networks have been praised for adding more diverse offerings in recent years, and where at least one show, Black-ish, does a bang-up job of representing a young black girl in all her complexity.)

When you're a young girl, trying to figure out how to be a person in the world, what you see onscreen really matters. It might especially matter if the character is already a young person like you are, so that you're encouraged to relate to them at that moment in time, not just as a role model for what you could be in the future. It's not a stretch to argue that when the movie or TV show is about and for young people, it's even more important that there's diversity on screen, and that characters don't fall into lazy, sexist tropes.